Structure of difluorotriphenylphosphorane.

C18H15F2P, M(r) = 300.29, orthorhombic, Pbcn, a = 6.105 (2), b = 16.634 (3), c = 14.356 (3) A, V = 1458 (1) A3, Z = 4, Dx = 1.368 Mg m-3, lambda(Mo K alpha) = 0.71069 A, mu = 0.194 mm-1, F(000) = 624, T = 294 K, R = 0.045 for 729 observed independent reflections. Difluorotriphenylphosphorane [(C6H5)3PF2] displays a trigonal bipyramidal geometry about the P atom, with the two F atoms occupying axial positions. The three phenyl groups in the equatorial positions are not 'geared' in a regular propeller arrangement; one of the three rings is twisted in the opposite direction to that of the other two.